Watch your attitude! Investigating the role of personalisation in social media campaigns from political actors to the electorate

Within democracies, a well-informed electorate builds the basis for political decisions and behaviour. Understanding the impact of media developments in political communication is, therefore, fundamental. Through digitisation, research on online political campaigning contributed to a better understanding of potential chances and risks for democratic societies. Especially social media, nowadays, is one of the main information sources for younger generations but also an essential communication channel for older generations. Hence, potential manipulations through personalisation or misinformation using data-based strategies need to be critically reflected and considered in empirical research. Based on theoretical assumptions of attitude biases on processing of information (motivated reasoning) and media exposure (selective exposure), this dissertation aims to contribute to a better understanding of personalisation in political communication on social media and its effects on political reasoning processes of the electorate. To answer, which role personalisation on social media might play in this context, a multimethodological approach was implemented. This thesis includes five original research studies investigating (1) topic diversity of paid and organic social media campaign content, (2) personalised advertising effects on social media, considering personality traits, existing attitudes, and (3) affective wording, (4) longitudinal relations of political social media exposure, attitudes, and voting, and (5) how to assess underlying political value orientations as one factor shaping the processing of personalised political information. The empirical research conducted explores various factors political actors make use of to align rhetoric elements algorithmically or strategically with the predispositions of both political and personal nature among the electorate. The overarching results of this cumulative doctoral thesis show that political attitudes are crucial for citizens’ political social media exposure as well as information processing and might be (mis-) used to target and persuade voters. Based on this, the role of digital personalisation is described considering perspectives of political actors and the electorate – outlining personal and political predispositions within the communication process. Due to the central role of existing preferences, like political values or attitudes, a measure of political predispositions was developed and introduced. Overall findings are summarised within a theoretical framework encompassing pertinent factors and their relationships, laying the groundwork for an in-depth examination of digital personalisation in the realm of political social media campaigns.